<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 复合选择器 */
        p.hello{
            color: red;
            font-weight: bold;
        }
        h2#welcome{
            background: pink;
        }
        /* 组合选择器，也称为集体声明 */
        span,p.world{
            color: red;
            font-size: 30px;
            background: cyan;
        }
        /* 嵌套选择器 */
        /* div span{ */
        div > span{
            text-decoration: line-through;
        }
        /* 伪类选择器 */
        /* a:link{
            color: black;
        }
        a:visited{
            color: red;
        }
        a:hover{
            color: green;
        }
        a:active{
            color: blue;
        } */
        a:link,a:visited{
            color: black;
            text-decoration: none;
        }
        a:hover,a:active{
            color: blue;
            text-decoration: underline;
        }

       
    </style>
</head>
<body>
    <p class="hello">aaa</p>
    <div class="hello">bbb</div>
    <p>ccc</p>
    <span>ddd</span>
    <h2 id="welcome">eee</h2>
    <p class="world">fff</p>
    <div>
        <span>ggg</span>
    </div>
    <div>
        <p>
            <span>hhhh</span>
        </p>
    </div>

    <a href="http://www.qaaaq.com">腾讯</a>
</body>
</html>